Examine source code of Smart Tabs

{
  "manifest_version": 3,
  "name": "Smart Tabs",
  "short_name": "smart-tabs",
  "version": "1.0.23",
  "description": "Smart Tabs replaces your new tab page with a powerful dashboard that automatically groups your open tabs by website.",
  "icons": {
    "16": "/icons/icon16.png",
    "48": "/icons/icon48.png",
    "128": "/icons/icon128.png"
  },
  "permissions": [
    "tabs",
    "bookmarks"
  ],
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "sandbox": {
    "pages": [
      "sandbox.html"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "smart-tabs@itcaat.github.io",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}